Progression of active trachoma to scarring in a cohort of Tanzanian children

Abstract

Risk factors for the incidence of scarring are needed to inform trachoma control programs in countries hyperendemic for this blinding disease. A cohort of pre-school children with constant, severe trachoma, and an age, sex, and neighborhood matched cohort of children without constant severe trachoma were followed for seven years to determine the incidence of scarring. The incidence of scarring in the children with constant severe trachoma was 29.2% versus 9.6% in the comparison group. In a model adjusting for multiple factors, significant predictors of scarring were increasing age, female, and constant severe trachoma (OR = 4.85, 95% CL = 2.05, 11.40). Infection with C. trachomatis at follow up was also associated with scarring in both groups of children. It is likely that these children have a different host response to infection, and represent a subgroup at high risk for the blinding complications of trachoma. Reducing exposure to infection in the community through antibiotics and changes in hygiene practices is still the most promising control strategy.

Risk of trachomatous scarring and trichiasis in Gambians varies with SNP haplotypes at the interferon-gamma and interleukin-10 loci

“…The majority resolve the infection without permanent sequelae. However, a subgroup of individuals develop more severe and persistent clinical disease in response to infection, 4,5 and are more likely to develop conjunctival scarring and trichiasis in later life. 6 The reasons for this heterogeneity in susceptibility to chlamydial infection and disease progression following a rather uniform bacterial exposure remain incompletely understood.…”

Cytokine and Fibrogenic Gene Expression in the Conjunctivas of Subjects from a Gambian Community Where Trachoma Is Endemic

“…Scarring and trichiasis develop in a minority of individuals, suggesting that variations in susceptibility are important. Severe inflammatory trachoma is associated with increased risk of cicatricial complications later in life (14,40).…”

Trachoma as cause of blindness: literature review

“…In hyperendemic areas, a subgroup of children, about 8-10%, seem to have constant infection and persistent severe inflammation (26)(27)(28) The incidence of scarring is nearly five times higher in these children than in children with active trachoma, but without severe inflammation [29]. In addition, scar formation can continue to develop in people living in areas that are not endemic [30], suggesting that the tissue damaged by infection with chlamydia can undergo progressive healing after injury by other bacterial pathogens [31].…”